Method and apparatus for making propeller shafts



Julyzf-l, 1934. H 1 WAISNER 1,967,487

METHOD AND APPARATUS FOR MAKING PROPELLER SHAFTS Filed March 2o, 1930 s sheets-sheet 1 July 24, 1934. H, WA|5NER 1,967,487

METHOD AND APPARATUS FOR MAKING PROPELLER SHAFTS Filed March 20, 1950 3 Sheets-Sheet 5 Patented July 24, 1934 UNITED STATES PATENT OFFICE METHOD AND APPARATUS FOR MAKING PROPELLER SHAFTS Application March 2o, 1930, Serial No. 437,354

39 Claims.

My invention relates to seamless metal tubing for propeller shafts and has specialreference to a method and apparatus for preparing propeller shafts wherein the inequalities in wall thickness 5 are arranged hellcally along the wall of the tube, whereby improved static and dynamic balance is imparted thereto.

In the production of seamless metal tubes, the wall along one side of the tube is invariably thicker 19 than the other, thus causing the center of gravity of the tube to fail to coincide with the geometric center of the outer surface thereof. When such tubes are mounted as propeller shafts considerable vibration develops as a result of their rotation at high speeds. These vibration difficulties increase as the rate of rotation of the shaft increases. moves toward vehicles of greater speed, it becomes increasingly important to have propeller shafts of greater dynamic balance. This I have accomplished by twisting the tube between its ends, to helically arrange the opposing heavy,r and light walls of the tube along its length. `In this manner, the heavy wall is arranged to lie in substantially equal proportions on all sides of the tube, materially improving the dynamic balance thereof.

A further source of difficulty with tubes of this character is that the mandrel marks lie parallel 30 to the fiber of the metal which often results in materially reducing the strength of the tube. The older methods of forming the tube almost invariably cause decarbonization of the inner surface, further reducing the strength thereof.

One of the objects of the invention is the provision of a propeller shaft having the inequalities in wall thickness arranged helically along the Walls of the tube to improve the dynamic balance thereof.

I have also aimed to provide a seamless propeller shaft wherein the mandrel marks lie at an angle with respect to the fiber of the metal.

Another object is to provide an `improved method for twisting ya tube, without substantial relative movement between the opposed inner and outer surfaces of the tube, whereby the inequalities are helically positioned on the inner wall thereof.

A still further object of the invention is the provision of a method of forming a propeller shaft As the trend in automobile constructionv wherein decarbonization of the inner surface of the tube is substantially avoided.

Another object of the invention is the provision of a method for forming a propeller shaft wherein the mandrel marks lie at an angle with respect to the fiber of the metal.

I further aim to provide an apparatus forl making propeller `shafts having means for progressively twisting a tubular blank andsimultaneously drawing the same to a different diameter.

Another object of the invention is to provide an apparatus for forming propeller shafts having a rotatable drawing die and rotatable mandrel wherein the mandrel is in contact with the tube over only a relatively small area thereof at any given time.

Another object is the provision of an apparatus for making propeller shafts having spaced drawing dies, one of the dies being varranged to hold the tube from rotation and one to permit rotation of the tube, a rotatable mandrel positioned in the last mentioned die, and unitary means for rotatingone end of the tube and drawing it through the dies.

Other objects and 'attendant advantages will become apparent to those skilled in the art from the following description and the accompanying drawings in which- Figure 1 is an elevation partly in section showing the complete assembly for drawing and twisting the tube;

Fig. 2 is an enlarged view of the. holding and drawing dies;

Fig. 3 is a section on the line 3-3 of Fig. 1 through the holding die;

Fig. 4 is a section on the line 4 4 of Fig. 1 showing 'the rotating die;

Fig. 5 is a section through the tubewhere it passes through the dies;

Fig. 6 is a Yperspective view of a tube showing in dotted lines the center of the heavy side thereof;

Figs. 7 and 8 are sections on; the lines 7-7 and 8-8 of Fig. 6 showing the manner in which the heavy section ofthe wall lies along one side of the tube;

Fig. 9 shows the manner in which the heavy side of the wall of the tube shown in5Fig. 6 would be arranged if manufactured by my improved method;

Figs. 10 and 11 are sections on the lines 10--10 and 11-11 of Fig. 9 also showing the manner in which the heavy side of the wall is directed helically along the wall of the tube by my improved method; and y Fig. 12 is asection through a second holding die which may be employed for the second pass of the tube through the drawing mechanism.

The invention contemplates in a general way the provision of a method of axially twisting a seamless tubular metal blank to arrange any inequalities in wall thickness helically along the walls of the tube and to draw the tubular blank to a desired size in such a manner as to cause the mandrel marks to lie at an angle with respect tothe fibe'r of the metal. Referring to Figs. 6-11, inclusive, the numeral 13 designates a tube as formed in the usual manner having a thickened side, the center of which is designated by the numeral 14. Figs. 7 and 8 show the manner in which this thickened portion lies substantially lengthwise of the tube. Fig. 9 shows the manner in which the thickened portion of the tube, as indicated by the line 14, will be helically dis- 'posed along the walls of the tube when the tube is prepared according to'my invention. Figs. l0 and 11A shows the manner in which the thickened portion is disposed around the center of the tube.

While the invention is not strictlylimited to seamless tubes it will doubtless be found to be of the greatest advantage in connection with this type. 'I'he method may also be applied to welded tubing to insure soundness of welds and enhance the physical properties. cussion lis directed 4particularly to steel tubes, the method is generally applicable to tubes of any metal having suflicient strength to be usable for this purpose. The method also contemplates drawing the tube'in such a manner as to reduce t0 a minimum the contact area between the mandrel and the inner surface of the tube. By so doing, thejdecarbonization of this surface is reduced to a minimum.i Of particular importance to the method is the manner in which the twisting operation is accomplished. The twisting, which may alvantageously vbe done in a progressive manner as will hereinafter be set forth, should beso carried out that relatively little movement occurs between opposed inner and outer surfaces of the metal.

The invention also contemplates the provision of a machine for carrying out the method wherein the tube is progressively twisted and drawn simultaneously. A holding die and a rotatable drawing die are provided and means for simultaneously twisting the forward end of the tube and drawing the tube through the dies., ,The holding die serves to prevent the rear end ofthe tube from turning, while the rotatable drawing die is permitted to turn as the front end Iof the' tube is rotated. A rotatable mandrel is positioned within the rotatable die in such amanner as to have contact with the inner surface. of the tube only within this die. In this manner the tube is held firmly between the mandrel and die,

Though the disness which, prior to the twisting step lie parallel to the axis of the outer surface of the tube, are directed in the form of a helix along the walls of the tube. This step contemplates a rotative movement about the longitudinal axis of the tube axially, the full cross-section of metal being displaced and theopposing inner and outer surfaces of the tube passing through a corresponding and identical movement. This movement is in contradistinction to a movement in which the opposing inner and outer surfaces of the tube have a movement with respect to each other. A movement such as I obtain will cause the thicker Wall portion of the tube to project in the form of a helix on the surfaces `of the tube. The tube is then passed through a' reducing die or dies wherein the tube is reduced to a desired diameter. The drawing operation also causes the irregularities in wall thickness to project from the inner surface of the tube 'and causes the outer surface to be truly' cylindrical. These two steps may be carried on separately or simultaneously as desired. A suitable machine adapted to carry out these steps in a simultaneous manner is shown in Fig. 1. A

Referring to the drawings, Fig. 1 shows a conventional tube drawing bench, designated generally by the numeral 15, having a horizontal bed 16 and suitable legs 17 and 18 for supporting the bench. A driven shaft 19 serves to support a sprocket gear 20 having an endless driving chain 21 trained thereover. Cogs 22 on the sprocket 20 engage the chain 21 and act to move the latter with the shaft 19. A second sprocket, not shown, is supported upon a shaft 23 and serves to support .the opposite end of the endless chain 21. A chuck carriage 24 is supported on the upper side of the bench 15 through a plurality of wheels 25 which rest upon the upper edges 26 of the bench 15 and a wheel 25a therebeneath. The chuck carriage is adapted to move from end to end of the bench upon the wheels 25. A draft arm 27 is pivotally supported upon the axle 28 of the rear wheels 25 and is provided at its outer end with the hooks 29 adapted in its lower position to engage with links 30 of the chain 21. When so engaged movement of the chain 21 to the right, facing Fig. 1, serves to move the chuck carriage 24 toward the right end of the bench 15. Suitable means such as wheel 25a may be provided for maintaining the chuck carriage 24 in firm contact with the upper edge 26 of the bench 15. A chuck 31 having jaws 32 therein is rotatably secured within the chuck carriage 24 upon a chuck shaft 33, through a nut 34 engaging a threaded end 35 thereof, the nut 34 bearing against a thrust bearing 36 which permits the shaft 33 to rotate with` a minimum amount of friction. 'A gear 37 is iixedly positioned on the shaft 33 and is arranged to engage a gear 38 adapted to be driven by a motor 39. Thus, through the agency of the motor 39, thegears 38 and 37 are driven rotating the chuck 31 and jaws 32. Any suitable means may, however, be employed for rotating the chuck 31 intimed relation to the drawing movement as hereinafter described. The forward end 40 of a tube designated generally by 41 is engaged by the chuck jaws 32 in any suitable or desired manner so that rotation of the chuck 31 will cause rotation of the forward end 40 of the tube 41.

A die support 42 is suitably positioned upon the drawing bench 15 and is fixedly secured thereto. The forward end of the die support is provided with a central opening 43 through which the tube 41 is adapted to pass. The opening 43 ShQllld be considerably larger than the tube 41 so that there is no contact between the support 42 and the walls of the tube. A drawing die 44 is positioned within the die'support 42 behind the opening 43 and is provided with suitable faces 45 to reduce the tube 41, through the drawing operation, to the desired size. A thrust bearing 46 is positioned between the die support 42 and the die 44 in such a manner as to permit free rotation of the die 44 against the pressure of the drawing operations. A holding die 47 is positioned near the rear end of the die support 42I and is provided with a centrally located, straight ribbed opening 48 through which thetube 41 is arranged to pass before entering the drawing die 44. The diameter of the tube is reduced to a certain extent within this holding die, though this is by no means essential, the primary object of the die being to prevent rotation of the tube 41 at this point. The die 47 is secured within the die support 42 by means of a plurality of keys 49 -which prevent relative movement between the die support 42 and the die 47. The

general shape and mounting 'of the dies 44 and 47 is shown more in detail in Figs. 2, 3, and 4 presently to be discussed.

A mandrel bracket 50 is fixedly secured to the Y drawing bench 15 and is provided with a suitable opening 51 within which is rotatably positioned a mandrel bar 52 through nuts 53 positioned upon a threaded end 54 of the mandrel bar4 52. thrust bearing 55` serves to permit the free rotation of the mandrel bar 52. The forward end of v the mandrel bar 52 is provided with a mandrel 56 which is shown more in detail in Fig. 2. The mandrel bar 52 projects inside the tube 41 and supports the mandrel 56 within the drawing die 44, the mandrel 56 determining the inside diameter of the tube 41 after the drawing operations have been completed. The mandrel bar 52 should be suitably supported to permit a small amount of lateral movement for the mandrel 56 to accommodate the latter for the displacement of the thickened portions of the tube 41.y The natural springiness of the mandrel bar will usually be suiiicient to provide this lateral movement.

Referring to Figs. 2, 3 and 4, which show the two dies and the die supporting section, straight ribs 57 are shown o n the surface of the ,holding die 47 and a space 58 is provided between' the holding die and the drawing die 44. The mandrel 56 is so positioned that the forward end thereof will be within the drawing die 44,.'causing the metal of the tube 41 to be reduced to pass between the surfaces of the mandrel 56 and the drawing die 44.

In operation, the forward end 40 of the tube 41 is inserted through the dies 47 andf44 and grasped by the jaws 32 of the chuck- 31, the carrage 24 being moved to the left to permit this. The draft arm 27 is then engaged with the links 30 of the chain 21 and the motor 39 is caused to rotate the chuck 31. The forward end of the tube 41vis, by this operation, drawn away from the die support 42 and at the same time is rotated. While the chuck 31 may be rotated in either direction if desired, I have found that it is preferable to turn`I the forward end 40 of the tube in a clockwise direction, viewed from the right hand end ofthe machine, when propeller shafts are beingvmanufactured, since this gives the tube a right hand twist and permits the tube to subsequently be employed to better advantage as a propeller shaft wherein clockwise motion is being transmitted.' Asthe forward end 40 of the 4tube 41 is drawn outward through'the Vdies'. v47

and 44 the ribs 57 of the die 47 are pressed into the metal, as shown at 59 in Fig. 5. This prevents the rear end 60 of the tube 41 from rotating with the rotary motion of the front end of the tube. There must consequently be a twisting action somewhere between the holding die 47 and the forward end 40 of the tube. This twisting action falls in the space 58 between the holding die 47 and the drawing die 44 since the metal at this point is relatively soft as compared with the metal after it has passed through the drawing die 44. The drawing die 44 being rotatable on the thrust bearing 46, the rotation of the forward end 40 of the tube 41 is transmitted back into the space 58. The tube between the drawing die 44 and the forward end 40 thereof will be relatively hard as compared with the rear end 60 of the tube, due to the cold working operations performed upon it, while the metal in the space 58 will be of intermediate hardness, and certainly will be the softest portion of the tube between the die 47 and the forward end of the tube. The mandrel 56 is so arranged and positioned as to be rotatable with the drawing die 44 and with the movement of the forward end 40 of the tube. It is also of such size as to bear against the inner walls of the tube only within the drawing die 44. 'I'his leaves the metal in the space 58 free both on its outer and inner surface and, the metal being soft, the tube at this point is bent at an angle on the arc of the circumference, dependent upon the ratio between the linear movement of the chuck 31 and the rotary movement thereof. .I have found it convenient to draw the tube through the dies at a linear speed of about 10 feet per minute and have provided one revolution of the chuck 31 to about twenty inches of such linear movement. By bringing the mandrel 56 into contact with the die 44 and permitting both of these to rotate with the rotation of the forward end 40 of the tube I provide a displacement of the metal within the walls of thetube which is different from that obtained by other methods. Where a tube is drawn through a stationary or fixed die, the surface of .the tube directly in contact with the die is caused to Imove with respect to other portions of the tube when motion is imparted to the tube because the surface sticks to the die and resists movement. If rotative movement is imparted to the tube in a 'stationary die, the movement of the fibers in contact with the surface of the die will be retarded so as to result in relative movement between the surface fibers and fibers further into the body of the metal. However, in" the present construction the die is mounted for free rotation-and rotates with the tube so that the only displacement of the metal is in a longitudinal direction. However, the fibers are bent so as to lie at an angle with the longitudinal center line of the tube, this bending operation taking place without` any relative movement between the fibers. 'Ihe fibers are bent at an angle depending upon the rotation imparted to the tube, but have no relative movement with respect to each other. It will be plain that the inner and the outer surfaces of the tube 41 are maintained in fixed relation to each other by the mandrel 56 and thedie 44. Thereis-consequently nowrel'ati'v'e l'movement between these surfaces at4 this point. In like manner, the depressions 59 in the tube caused by the ribs 57 of the holding die prevents twisting movement of the metal within the die 47, consequently movement of the metal in the area 58 is substantially at right angles to the radius of the 150 outer surface of the tube. 'Ihis movement is shown byI the dotted line 61 of Fig. 5 which is intended to indicate the direction of the fiber of the metal. The forward ends 62 of the depressions 59 are likewise deiiected upon entering the area 58 as `shown in Fig. 5. In this manner it will be seen that the ber of the metal 'as well as the inequalities in thickness of the tube wall will be directed helically along the wall of the tube before the tube has been drawnthrough the drawing die 44. Movement between the tube 4l and the mandrel 56 is entirely linear since the mandrel is permitted to rotate with the rotation of the tube. For this reason the mandrel marks will not be formed on the inside of the tube in the form of a helix but will extend parallel to the length of the tube. Consequently, these mandrel marks will lie across the ber of the metal at an angle and not lie parallel thereto, as is the case with other types of drawing operations.

Obviously, many changes may be made in the construction as shown. For example, the holding die 47 may be rotated instead of rotating the chuck 31. However, in that case the distance between the die 47 andthe drawing die 44 should be relatively small to prevent buckling of the soft tube in the space 58. In like manner both the holding die 47 and the chuck 31 might be rotated in opposite directions thereby accomplishing the same results. The distance between the holding die 47 and ,the drawing die 44 is not particularly important so long as they are not positioned so closely together as to result in rupture of the metal. I have found that this distance should usually be not less than about one inch. Generally speaking, however, in steel tubes the higher the carbon content of the tube metal the greater the space 58 should be. However, the greater this space the more waste tube results from the drawing operations. It is, therefore, a compromise as to the proper distancebetween these two points, the distance depending upon the particular conditions under which the machine is being operated.

vI have found that in the normal operation of the machine with low carbon steel for example of .08 to .l2 C the tube may be reduced, for example, froma diameter of 21/2 inches at the rear end 60 to a diameter of two inches at the forward end of the tube by a single pass through the die.. 47 an`d 44. -Theprticular dies shown are so arranged that th olding die 47 reduces the diameter of the tube from 2% inches to substantially 2% incheswhilegthe drawing die 44 further reduces the diameter of the tube to two inches.

.However, when the tube is of high carbon steel it is often necessary to make more than a single pass of the tube through these dies. Under such circumstances the dies 47 and 44 are so arranged as to reduce the size of the tube, for example, from 2*/2 inches at the end 60 thereof to 2% inches on the forward end of the tube. The tube is then annealed and treated in the usual manner for a second drawing operation. In this second drawing operation a smooth faced holding die 63, such as shown in Fig. 12, is employed. In this instance the face 64 of the die is made considerably longer to increase the friction between the tube 41 and the die and prevent rotation thereof. In this second pass oi.' the metal through the dies the tube may be given a further amount of rotation if desired or may bedrawn laterally through the dies without rotation. 0n this second pass' through the dies the tube is reduced,.for example,

from 2% inches to two inches in diameter, dies of suitable size being employed for the purpose.

The mandrel 56 is in contact with the inner wall of the tube 41 through only a small proportion of its length. 'Ihis resultsin a minimum amount of rubbing between the two surfaces as a result of which substantially no decarbonization occurs on the inner surface of the tube 41.

By these drawing operations the physical properties of the tube are substantially increased and the tube may be made substantially lighter because of this increased strength. The fact that the mandrel marks lie at an'angle with respect to the fiber of the metal materially reduces the danger of tube rupture and weakness, thereby resulting in a tube of substantially more valuable properties. Even should decarbonization of the surface occur the fact that the mandrel marks lie across the iiber of the metal ysubstantially increases the strength of the tube, at least partially recompensing for the decarbonization of the surface.

The twisting operations, whereby the inequalities in wall thickness are directed helically along the wall of the tube, results in highly improved static and dynamic balance thereby enhancing the tube for use as a high speed propeller tube, by causing the line through the centers of gravity to lie in a helix about the axis of the outside circumference, instead of parallel with it as would otherwise be the case.

While I have thus described and illustrated one embodiment of Amy invention I am aware that numerous alterations and changes may be made therein without materially departing from the n spirit of the invention and I do not wish to be limited except as required by the prior art and the scope of the appended claims.

I claim:

l. The method for making propeller shafts having improved static and dynamic balance which includes, drawing ametal tube from one diameter to another, and simultaneously axially twisting the tube to helically direct the metal in the area in which this drawing operation occurs, to produce a helically iiber tube.

2. The method for making propeller shafts having improved static and dynamic balance which includes, reducing the diameter of a tubular blank through a drawing operation, and simultaneously axially twisting the tube to helically direct the metal in the area in which this drawing operation occurs, to produce a helically fiber tube.

3. 'I'he method for making propeller shafts 130 having improved static and dynamic balance which includes, forming a metal tube, twisting said tube axially by helically displacing the metal equality throughout the wall thickness, and sizing said tube.

4. The method for making propeller shafts having improved static and dynamic balance which includes, forming a metal tube, progressively twisting said tube axially betweenspaced dies to helical1y`direct the inequalities in wall 140 thickness on the inner surface of the tube, and size the tube.

5. The method for making propeller shafts having improved static and dynamic balance which includes, forming a metal tube, progres- 145 sively twisting said tube axially, when cold, so as to dispose the inequalities in wall thickness helically along the inner surface ofthe tube, and thereafter drawing the tube to size the same.

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6. The method for makingpropeller shafts having improved static and dynamic balance which includes, forming a steel tube, twisting said tube axially in a limited area and progressively from end to end, when cold, and thereafter drawing the tube to size the same.

7. The method for making propeller shafts having improved static and dynamic balance which includes, forming a seamless steel tube, twisting said tube axially in a limited area and progressively from end to end, when cold, and thereafter drawing the tube between a die and a mandrel to size the same.

8. The method for making propeller shafts having improved static and dynamic balance which includes, forming a metal tube, twisting said tube axially in a limited area and progressively from end to end, when cold, and thereafter sizing said tube through cold working methods.

9. The method for making propeller shafts having improved static and dynamic balance which includes, forming a steel tube, twisting said tube axially in a limited area and progressively from end to end, when cold, and thereafter cold drawing the tube between a die and a mandrel to size the same.

10. The method for making propeller shafts having improved static and dynamic balance which includes, forming a seamless steel tube, progressively twisting said tube axially, when cold, around a floating mandrel, and thereafter sizing said tube through cold working methods.

11. The method for making propeller shafts having improved static and dynamic balance which includes, forming a steel tube, progressively twisting said tube axially, when cold, by helically displacing the metal equally throughout the wall thickness to helically dispose the inequalities of wall thickness on the inside of the tube, and thereafter drawing .said tube in the cold to a desired size.

12. The method for making propeller shafts having improved static and dynamic balance which includes, forming a seamless steel tube, progressively twisting said tube axially, when cold, around a loosely fitting mandrel, and thereafter drawing the tube between a die and a mandrel to size the same.

13. The method for making propeller shafts having improved static and dynamic balance which includes progressively gripping the Ytube in a small area to prevent rotation of a portion of the tube, sizing the tube by passage through a reducing die, and imparting longitudinal and rota'- tive movement to the tube to cause said operations to be performed on said tube in succession.

14. The method for making propeller shafts having improved static and dynamic balance which includes progressively gripping the tube by constriction in a small area to prevent rotation, reducing the diameter of the tube at a point spaced from the gripping point, imparting longitudinal movement kto the tube to cause the tube to be gripped and then reduced in diameter, and imparting rotation to a portion of said tube to cause the fibers of the metal to be helically directed in the area between the gripping point and the reducing point.

15. The method for making propeller shafts having improved static and dynamic balance which includes progressively holding a tube against rotation by constriction in a limited area,

imparting longitudinal and rotative movement to the tube to reduce the diameter thereof and progressively twist the tube between the point at which it is held and the point of reduction.

16. The method for making propeller shafts having improved static and dynamic balance which includes passing a tube longitudinally through a fixed holding member and through a rotatable reducing die located in spaced relation thereto, and circumferentially twisting the tube in the space between the holding member and the die to helically direct the ber of the metal.

17. The method for making propeller shafts having improved static and dynamic balance which includes reducing the diameter of a tube at two closely spaced longitudinal points and helically directing the fiber .of the metal in the area between the points of reduction by rotation of one portion of the tube.

18. The method for making propeller shafts having improved static 'and dynamic balance which includes simultaneously reducing the diameter of a tube and holding it against rotation, reducing the diameter of the tube a second time at a point spaced from but closely adjacent to the point of rst reduction, and helically directing the fiber of the metal in the area in which the metal is in a state of uxby imparting relative rotative movement between the adjacent, parts of the tube.

19. The method for making propeller shafts having 'improved static and dynamic balance which includes, forming a seamless steel tube, twisting said tube axially in 'a limited area and progressively from end to end when cold around a loosely fitting mandrel, and thereafter drawing the tube between a die and a mandrel to size the same.

20. A machine for simultaneously drawing and twisting tubing comprising a draw bench having the usual draw chain and die head, a xed fluted die secured in said die head, a revolvable reducing and drawing die rotatably mounted in said die head in cooperative relation Ito said fixed fluted die, a draw carriage supported for movement along the vdraw bench and connectible with the draw chain to be actuated thereby, tube engaging pliers mounted and interconnected with the carriage so as to be constrained to move longitudinally therewith while free to rotate relative thereto and means for rotating said pliers as said .carriage is moved longitudinally of the draw bench.

21. A machine for simultaneously drawing and twisting tubes comprising a draw bench having the usual draw chains and die head, a drawing die mounted in the die head, a draw carriage supported for movement along the draw bench and connectible with the chain to be actuated thereby, tube engaging pliers mounted on and interconnected with the carriage so as to be constrained to move longitudinally therewith while free to rotate relative thereto, means on the carriage for rotating the pliers and means' on the opposite side of the drawing die from the pliers for positively holding a portion of the tube against rotation.

22. A machine for simultaneously drawing and twisting tubing comprising a drawing die, means for pulling the tubing through the drawing die and imparting rotation thereto and means for positively holding a. portion of the tubing against rotation. Y

23. The hereindescribed method of drawing and twisting tubes which consists in producing relative rotation between spaced portions of the tubing and simultaneously drawing the tubing intermediate said spaced portions.

24. The hereindescribed method of producing .5 tubing which consists in drawing the tubing and subjecting the portion of the tubing being worked in the drawing zone to a twisting action.

25. The hereindescribed method of drawing and twisting tubes which consists in holding a portion of the tube against rotation, rotating a spaced portion thereof and simultaneously subjecting an intermediate portion of the tube to a drawing operation.

26. A machine for simultaneously drawing and twisting tubing comprising a draw bench having the usual draw chain and die head, a fixed iiuted die secured in said die head, a revolvable reducing and drawing die rotatably mounted in said die head in cooperative relation to said fixed fluted die, a draw carriage supported for movement along the draw bench and connectible with the draw chain to be actuated thereby, tube engaging pliers mounted and interconnected with the carriage so as to be constrained to move longitudinally therewith while free to rotate relative thereto, a motor and gearing mounted on the car- 'riage and connected with the pliers for rotating the same as the carriage is moved longitudinally of the draw bench.

27. A machine for drawing and twisting tubing comprising a i'lxed fluted die, a cooperable drawing die and means for pulling the tubing through the dies and imparting rotation thereto.

28. A machine for drawing and twisting tubing comprising a draw benchlhaving the usual draw chain, a drawing die supported in cooperative relation to the draw bench, a draw carriage supported for movement along the bench and connectible with the draw chain to be actuated thereby, tube engaging pliers mounted lon and interconnected with the carriage .so as to be constrained and moved longitudinally therewith while free to rotate'relative thereto, means for rotating the pliers as the carriage is moved longitudinally during the drawing operation and 4means cooperable with theportions of the tube being fed to the drawing die to positively hold such portion against rotation.

29. A machine for drawing and twisting tubes comprising a drawing die, tube engaging pliers, means for moving the tube engaging pliers longitudinally to pull the tube to be drawn through the drawing die, means for rotating the tube engaging pliers during the drawing operation and means cooperable with the tubing as it is fed to the drawing die for positively holding the portions of the tubing being fed to the drawing die against rotation.

30. An apparatus for forming tubes comprising a holding die shaped to draw thetube and hold the same against rotation, a rotatable die spaced therefrom and shaped to continue the drawing of I, said tube, means for passing said tube through ing said tube longitudinally through both of said dies and imparting rotative movement to the portion of said tube forward of said rotatable die.

32. An apparatus for forming tubes comprising axed holding die shaped to draw a tube to a smaller diameter and having a plurality of ribs for holding the tube against rotation, a rotatable die spaced therefrom and shaped to continue the drawing of said tube, a rotatable mandrel cooperable with said rotatable die, and means for simultaneously passing said tube longitudinally through both of said dies and imparting rotative movement to the portion of said tube forward of saidrotatable die.

33. An apparatus for forming tubes comprising a die support, a holding die normally fixed in said support shaped to draw a tube and hold the same against rotation, a drawing die spaced from said holding die, means for rotatably supporting said drawing die on said support, a rotatable mandrel within said tube cooperable with said rotatable die, and means for simultaneously passing said tube longitudinally through both of said dies and imparting rotative movement to the portion of said tube forward of said rotatable die.

34. An apparatus for forming tubes comprising a holding die, a rotatable drawing die spaced therefrom, and means for simultaneously drawing a tube through the dies comprising means for moving said tube axially, and means for simultaneously rotating said tube.

35. An apparatus for forming tubes comprising a holding die, a rotatable drawing die spaced therefrom, and means for simultaneously drawing a tube-through the dies comprising means for moving said tube axially, and means for simultaneously rotating said tube comprising means for grasping one end of the tube, and means for imparting longitudinal and rotative movement to said grasping means.

36. An apparatus for forming tubes comprising a drawing bench, a holding die mounted thereon, a rotatable drawing die mounted thereon in spaced relation to said holding die, and means for simultaneously passing a tube through said dies, said means comprising a chuck secured to one end of said tube longitudinally movable on said bench, and means for independentlyrotating said chuck during its longitudinal movement.

37. An apparatus for making propeller shafts having improved static and dynamic balance comprising, a rotatable drawing die arranged to receive a tubular blank, a rotatable mandrel positioned within said blank and arranged to cooperate with said die to determine the inside and outside diameter of said tube, means for drawing said tube through said die, means for imparting axial motion to the forward end of said tube, and means to the rear of said die andspaced therefrom, for securing the rear end of said tube from rotation, whereby said tube twisted between said die and said last mentioned means and subsequently drawn through said die to dispose the fiber helically along the tube.

38. An apparatus for making propeller shafts having improved static and dynamic balance comprising, a rotatable drawing die arranged to receive a tubular metal blank, a mandrel positioned within said blank and arranged to bear against the wall of said tube within said die to determine the inside and outside' diameter thereof, means for drawing said tube through said die, holding means through which said tube is arranged to pass arranged to grip the tube and prevent turning thereof, said means being rearwardly spaced from said die, and means for imparting axial motion to one end of said tube.' 150 tube, means for drawing said tube through said dies, means on said holding die for holding against rotation a portion of the tubespaced rear- Wardly of the rotatable die, andmeans for imparting rotation and axial motion to one end of said tube whereby the latter is twisted between said holding die and said rotatable drawing die, to dispose the inequalities and bers helically through said drawing die to reduce to desired size.

HORACE L. WAISNER.

along the tube, and is subsequently drawn 

